Re-evaluation of the genus Biapertura Smirnov, 1971 (Cladocera: Anomopoda Chydoridae) Author Sinev, Artem Y. text Zootaxa 2020 2020-11-26 4885 3 301 335 journal article 9373 10.11646/zootaxa.4885.3.1 de7c4264-09b0-4361-a7cb-04f80e6ddbe2 1175-5326 4296625 784B14D1-7B68-42F1-81A1-9EAB8DFD7E79 Biapertura lepida (Birge, 1982) comb. nov. Birge 1982: 393–394, Pl. 13. Fig. 19. ( Alona ); Sinev 2013: 335–341, Fig. 4–7 ( Alona ). Type locality. Madisson , Wisconsin , USA . Type material. Non–existent. Material studied earlier. See Sinev (2013) for the list of material from USA and for detailed description. Short Diagnosis. Parthenogenetic female. Length of adult female 0.92–1.06 mm . Body ( Fig. 15G ) with height strongly increasing posteriorly; maximum height in the third fourth of the body; height/length ratio 0.52–0.6 in adults. Unlike in all other species of the genus, sculpture of valves as well-defined longitudinal lines. Postero-dorsal angle ( Fig. 15H ) with 9–12 groups of setulae, with 5–9 setules in each. Main head pores with PP about 1.2–1.5 IP in adults ( Fig. 15I ). Lateral head pores located about 0.7–0.9 IP distance from midline, at the level of anterior major head pore. Postabdomen ( Fig. 15J ) with convex postanal margin; maximum height after the postanal angle; length about 2.5 height; dorsal margin weakly convex in postanal portion and weakly concave to almost straight in anal one; distal part about 2.5–3 times longer than preanal one; postanal portion 2.5–2.8 times longer than anal one. Postanal margin ( Fig. 15K ) with 15–17 very slender denticles, each with 1–4 denticles along anterior margin. Postabdominal claw ( Fig. 15L ) with basal spine about 0.25 the length of the claw; unlike in all other species of the genus angle between spine and postabdominal claw itself about 15° only. Antenna ( Fig. 15M ) with basal segment of both branches 1.5 times longer than two others, subequal in length; spine on basal segment of exopodite signifi-cantly longer than middle segment; spines on apical segments as long as apical segments. Limb I with IDL seta 1 not claw-like, thin, about half length of seta 2 ( Fig. 15N ); seta e of endite 2 only slightly longer than seta f. Male unknown. Differential diagnosis. B. lepida clearly differs from all other species of the genus in postabdominal claw with basal spine almost parallel to the claw itself, and by IDL seta 1 being not claw-like, two times shorter than seta 3. Distribution and ecology. East USA , known from Wisconsin and North Carolina . Ecological preferences unknown.